Definition of «G protein»

G protein: These molecules have
been described as "biological traffic lights." Located
inside the cell, G proteins are able respond to signals
outside the cell -- light, smell, hormones -- and translate
(transduce) these signals into action within the cell.

Alfred G. Gilman and Martin Rodbell shared the 1994 Nobel
Prize in Physiology or Medicine for "their discovery of G-
proteins and the role of these proteins in signal
transduction in cells."